It's a post-apocalypse book. During the Cold War the US developed a supercomputer to fight for them. So did China and Russia. But the computer the US developed became self-aware, devoured the other two computers, literally went insane (the same way a human can), and gained complete control of the world, wiping out the entire human race except for five people that it's kept alive to torment for over 109 years because it absolutely despises humans. The story begins with the characters finally starting to figure out how they can escape and destroy the evil computer, AM, forever. It's an interesting story because as it progresses there's some fascinating character development which was really what I loved most about it since almost every character has some skeletons in the closet so you're never sure what to think of them until the end, and aside from it being a "Good fighting against evil," story, there's also a lot of focus on overcoming one's own shortcomings or major flaws and deciding if you're ever going to learn from your past or be doomed to repeat it.
The author also helped turn the book into a game for the PC which was absolutely phenomenal. He wrote the script and modified the storyline so it would translate well into a game, and he even voiced the evil computer which made it even better.